The Ninja-RPG Walkthrough: Part I - Foreword:

The
Ninja-RPGis a Browser based fighting simulator game, who takes on
the roll of a Ninja. Learn the way of Shinobi as you start as an aspiring
Academy Student. Fight your way to the top to become the Kage: the single shadow
that protects your village from any danger, or become your village's worst
nightmare as a wandering Outlaw of pure darkness.

This is a step by step
walkthrough on the official site, covering nearly everything.

For your village, choose one with a high amount of village regeneration to
help your training. The best choices in order are: Shroud, Glacier, and Current.
Village Regen Rates

The Quick Start Guide will help here if you have any trouble. Read it after
anyway to learn how to play.

Decisions

Level Holding

Starting off with the easy one, claiming levels can either be slightly
detrimental or beneficial to your training. (In this game, you choose when to
level up. When you level up, you get fully healed and slight stat boosts.) It's
simply recommended that you always claim them unless you're at the rank you plan
to stay at (explained below). However, if you plan to be incredibly active, you
can hold off on all of them until you're about to rank up. This can be used for
the jutsu requirement at AS or the many intelligence requirements.

Rank Holding

Additionally, rank holding is rather similar except more obvious. Don't rank
hold because it will just slow down training and any preparations you make for
the next rank won't be enough.

Main vs Alt

Choose who your alternate will be. Only play one of the accounts and use the
other one for ryo. The alternate will always be a special jounin to capitalize
on regeneration (so for that account, follow the guide until it's a special
jounin). It's best to decide this after you roll your bloodlines at genin.

Training Method

Decide whether you want to play this game frequently or not. If not, start
training weapon offense instead of defense after you get the right amount of
defense for the rank you plan to be (235 for chunin, 985 for jounin, and 2985
for special jounin). This makes you battle-able earlier, letting you fight in
the battle arena for quick, easy, small cash as well as travel around the map a
bit. If you do want to spend the time, though, you can keep training defense and
use the level 200 jutsu method. This pays off in the end when jutsu are much
harder to raise.

Rank

Last is the only hard decision you really have to make. Like most other
games, Ninja-RPG has choices for your character that aren't necessarily better
or worse. The most important of these is your rank. There are three: chunin,
jounin, and special jounin.

Chunin are arguably the easiest to play as. They require the least time to
maximize jutsu, home regeneration, and chakra/stamina pools. However, they take
the longest to maximize offense, defense, general stats, and have the smallest
chakra/stamina pools. They can attack/defend chunin and jounin.

Jounin are in the middle in all ways. They require an average time to
maximize jutsu, chakra/stamina pools, offense, defense, generals, and have
average chakra/stamina pools. They can attack/defend chunin, jounin, and special
jounin.

Special jounin are arguably the hardest to play as. They require the longest
time to maximize jutsu and chakra/stamina pools. However, they take the least
time to maximize offense, defense, generals, and have the largest chakra/stamina
pools. They can attack/defend jounin and special jounin.

The main reason being a special jounin is so hard is other players. Some of
the most competitive players are special jounin and have been playing since
close to the game's launch in January 2008. On the other hand, being a chunin
lets you avoid these players. As a side note, in quantity, there are more
competitive special jounin than chunin than jounin.